Engine swap 1990 525

[Dangeruss]

Have a 90 525, with a 5 speed standard transmission with 190k miles. Blew a head gasket last month and got very hot and cracked the head. Looking for a good replacement engine and found another 90 525 with an automatic. Any reason why I cant pull the engine out and swap transmissions and bolt it back in? I assume the block is the same and I can switch out the other parts to make the standard trans work on a motor with an automatic?

Sorry for the seemingly simple question, but just want to make sure. Have done motor/tranny swaps before on other makes, but don't know much about BMW's . . . yet.


Thanks

[632 Regal]

I see absolutely no problem with swapping the engines out. Same year and all is a bonus cause you wont have to deal with any year and sensor changes. Get as much as you can from the doner 'just incase' BMW is funny about that stuff.

[Dangeruss]

Thanks for the reply. Probably going to buy the whole car and part out what I don't need. The transmission is shot on the doner, so getting it fairly cheap.

[632 Regal]

Lots of parts! That is one good thing.

[genphreak]

Good thing? Until you end up fixing both and having 1 you like but don't need- and then more reasons to buy a third (etc.)

@Dangeruss; make sure it is the same engine type- in Australia '90 models could be M50 or M20 engines, swapping the later M50B25 into an M20B25 car is more complex as you need to replace the engine bay wiring and many other items (but the engine is better) so if you have all the parts in the donor it isn't too bad. The transmission/clutch may present some differences in this case though.

[Dangeruss]

Good thing? Until you end up fixing both and having 1 you like but don't need- and then more reasons to buy a third (etc.)

@Dangeruss; make sure it is the same engine type- in Australia '90 models could be M50 or M20 engines, swapping the later M50B25 into an M20B25 car is more complex as you need to replace the engine bay wiring and many other items (but the engine is better) so if you have all the parts in the donor it isn't too bad. The transmission/clutch may present some differences in this case though.

Yes, as, same motor and year, but an automatic as mine is a standard. Turns out the car on craigslist I was looking at is fairly beat up and runs terrible so I am still looking for a donor motor. I would like to upgrade to the M50, but it's more work then I am looking for right now.

[genphreak]

Ah. oh well :-( M50 is not much of an improvement really. M20 is an excellent and strong motor so sticking with it is not much of a compromise.

Upgrading shouldn't be too hard unless you pickup a '95, I'd go for a pre '94 vanos (non-EWS) or perhaps an M52B28 (cheap), M52B25, M50B30 if spending up. These one require the 'OBD1' conversion (a hybrid of the old and new wiring) and will give you real power and economy improvements.

You may probably know the following, but JIC- in hunting for a donor, don't worry too much about the engine if it runs alright. If the head gasket is good and it hasn't gone >150,000miles its unlikely to be trouble. I usually check the coolant for oil, bubbles on revving, type (colour should be blue or yellow, green may be ok but should force a closer look if worried about the maintenance history)- and age (look for buildups of gunk). Also, the oil- under the oil cap the cleaner the better. IMHO all BMW engines seem to last internally incredibly well, unless they miss oil changes of course.

[Dangeruss]

The engine had 210k and ran poorly. There were many other things that clued in to a abused car overall so I stayed away. Advertised it as a nice car that had a bad transmission. Said he did the head gasket and other things, but had no receipts.

Still looking. . . . .